If you have to pay, at least try to negotiate 1) a guarantee that the hackers won't just do it again sometime later, and 2) full disclosure / assistance in repairing your vulnerabilities so you have some kind of head start for the future. Outside of politically motivated hackers, this would probably be reasonably successful.
We are in the context of already having to pay. You are at their mercy no matter what, so the only value of any interaction with them is based on hoping they have incentive to maintain their promises to protect their reputation etc.
It's not a good situation to be in, but still, try to make the best of it.